1. Field of the Invention
The present invention relates to the wireless application protocol (WAP) environment and, more particularly, to an apparatus and a method of communicating messages and information between a server in a wide area network and a mobile station in a wireless communication network.
2. Description of the Related Art
Remote communication with individuals has become increasingly important in a mobile society. Early versions of wireless devices transmitted a signal to a paging device worn by the user. Early paging devices did little more than provide a beep indicating that a message had been sent to the user. The user then called a telephone number to receive the actual message. These early paging devices were replaced with text messaging devices that include a small display that permits the transmission of a text message, such as the message sender""s telephone number. While the text messaging device provided additional data to the user, the user still has to use a separate telephone to contact the message sender, or to take action in accordance with the message.
With the advent of wireless communications networks, a user can simply call any telephone number on his cellular phone from virtually anywhere, and, once connected, speak directly to another party. Some cellular xe2x80x9cphonesxe2x80x9d are even capable of transmitting and receiving data through an air link. These xe2x80x9cphones,xe2x80x9d more properly named as mobile stations, operate as mobile terminals and have features similar to those of desktop computer terminals, features such as the ability to access stock quotes, weather, and e-mail messages through the Internet. Typical mobile stations, however, have less powerful processors and memories than those of desktop terminals because they have severe size, weight and power consumption constraints. The amount of data and reliability of data transmission are also limited by the available frequency spectrum, i.e., the radio resources allotted to the mobile station.
To alleviate these problems, there has been implemented the Wireless Application Protocol (WAP) for handling the interface between a mobile station and a wireless network in a manner that optimizes the computing resources of the mobile station and the radio resources of the mobile network. According to WAP, the mobile station communicates messages, encoded in Wireless Markup Language, to a gateway server connected to the wireless network, which then translates the messages into a format understood by web servers in the wide area network.
However, prior art gateway servers do not efficiently and dynamically process data between the mobile stations and web servers as they often require costly hardware implementations for different content conversions, thereby limiting the number of features available to users of the mobile stations.
An object of the present invention is to provide a method and an apparatus for efficiently and dynamically processing data between a mobile station and a server in an area wide network.
An advantage of the present invention is that a gateway server may be adapted to convert new content types and use scenarios without requiring new hardware implementations. The advantage is realized by configuring servlets (written, for example, in Java(trademark)) to perform content conversions.
According to an aspect of the invention, the method uses Java(trademark) servlets in a gateway server to process resource requests from a mobile station and requested resources from an origin server in a wide area network. The servlets are arranged in a plurality of chains such that output from one servlet is processed by a subsequent servlet in the same chain. The servlets communicate with an administrator module, for invoking appropriate servlets, in the gateway server through an application programming interface. The servlets are configured to perform content conversions so as to adapt the requested content in accordance with user preferences, to optimize the content to a user device, to perform graphics conversions, or to automatically translate from one language to another, etc.
In one embodiment, there is provided a method for dynamically converting data between a mobile station in a wireless communication network and an origin server in a wide area network. The method includes sending from the mobile station to a gateway server a request for a resource located on an origin server in a wide area network. One or more servlets initiated in the gateway server are selectively invoked. The request is processed and information is dynamically generated related to the request by the one or more servlets. The processed request is sent by the one or more servlets to the origin server. The requested resource received from the origin server is then processed by the one or more servlets, which then generate a response including information indicating content type of the requested resource. The requested resource is thereafter converted from the indicated content type to another content type prior to transmission to the mobile station.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.